Pneumatic-dispatch power-control apparatus



Sept 14 1926.

I v J. 'r. COWLEY PNEUMATIC DISPATCH POWER CONTROL APPARATUS 2 Sheets-Sheet 1 Filed April 25, 1925 172])677/607" fez/77219.5 I

Sept. 14 ,1926.

Filed April 25,

1925 2 Sheets-Sheet 2 5 5 2 v 1 5 a 22 2. 7 2 7 2 of s E A R i 7 2 a 0% v 2 7 I M 73 a J I 6 J M J i. M M f 4 4 o w, 4 0. a 4 fa.

, Ja/wi/ed I CowZey w E fie fitbfya.

Patented Sept. 14, 1926.

* UNITED STATES "PATENTQFFIC'E.

JAMES T. COWLEY, or SYRACUSE; NEW YORK, ASSIGNOR To THE 'LAMSoN COMPANY,

or SYRACUSE, NEW YORK, A CORPORATION or MASSACHUSETTS.

PNEUMATIC-DISPATCH POWER-CONTROL ArrAaaTuS.

Application filed April 25,1925. Serial No. 25,766.

ly a valve locatedbetween the transmission 10 tube and an air exhauster or vacuum drum,

such valve normally cutting off carrierpropelling air flow through the tube when the tube is idle, although at all times permitting a continuous flow of relatively small volume insufficient to propel a carrier and known as the minimum flow, and a pneumatic,-for example a piston or diaphragm. which responds, either directly or indirectly, to change in pressure in the tube, due tothe momentary cutting ea or checking of the minimum flow of air incident to the insertion of a carrier inthe'tube, and which, by

such response, opens wide the valve to permit a full carrier propelling. air flow through the transmission tube.

In the form of apparatus described in the Libby patent the period during which the valve remains open is determined solely by the operation of a timing device. The present invention is intendedtozimprove the operation of devices. of this general type by eliminating the timing device and in place thereof providing means which is responsive directly to the change in pressure in the transmission tube, incident to discharge of the last carrier therefrom, vforinitiating closure of the controlling valve.

In the accompanying drawings a preferred embodiment of the invention is illustrated by way of example,- 1

Fig. 1 being a' diagrammatic elevation, partly in section,'sho'wing the improved controller installed between one tra-nsmlssion tube of a pneumatic system and the exhaust header thereof; 7 j I Fig. 2 is a vertical section to large Scale showing the parts normal position, the 7 main valve beingclosed; and r I Fig. 3 is a view similar to Fig. 1. but showing the parts as pOlsliiSl fid; a the in tant after discharge of the last carrier from the tube but before the main valve has closed. Referring to Fig. 1 of. the drawings, the numeral 1 indicates a portion of a central stat on desk provided with the dispatch term nal 2 forming a part of the sending transm ssion tube 3 leading totan outlying statron. The corresponding return transmission tube 4L is provided with the usual delivery terminal 5 and with an extension 6 which 00 .passes down through the top of the desk 1 and is connected with the power control. apparatus indicatedgenerally at 7. A suction tube 8 leads from the power control appara; tusto the usual Section drum orheader 9 in 0 whlch a vacuum is constantly maintained by means of a suitable exhauster, not shown. A continuous air passage 'or conduit is thus provided extending from the terminal 2 to the exhauster, that portion of the conduit provided by the tubes 3 and f constituting the carrier transmisison line. p

Referring to Figs. 2 and 3, the numeral 7 as above explained indicatesthe improved power controller as a'whole. This controller in the embodiment illustrated comprisesa hollow casing 10 having therein a chamber 10 which communicates freely at all times with the pipe 8'leading to suction header 9.

A substantially u shaped partition or septurn 11, comprising substantially parallel upper andlower walls 12 and13 respectively, separates the main body of the chamber 10 from an inlet chamber. 14 which communicates directly with the tube 6. v V

The upper and lower walls .12'and 13 of the septum 11 are furnished with aligned valve orifices 15 and 16 respectively (Fig. 3). A valve 17 of balanced type, hereinafter refered to as the main valve and' comprising spaced heads 18 and19, cooperates with the orifices 15 and 16, and controls the inward fiow of air through the transmission tubes 3 and 4 toward the exhaust header 9. Normally the valve 17 is closed so as to cut off carrier propelling air flow through the transmission tubes, but at all times a small continuous flowof air through the transmission tube is permitted by the provi- .Sion of?! c nduit 20j1eading directl frornthe 99 pipe 6 to the pipe 8 outside oi: the controller casing 10. While such an outside pipe s preferred, similar results may be obtained it desired by providing a small orifice through one of the walls of the septum 11 or alternatively by making the valve 1 heads 1.8 and 19 somewhat smaller than the valve orifices so as to allow leakage of air past the valve heads. 7 I

The upper wall 21 oft-he controller casing is flared outwardly and upwardly to provide a shallow receptacle 22 of generally circular contour which has a radial flange at its edges. This flange TOURS a scatter the outer edge of a flexible diaphragm 2a which is clamped between t-l'ic 23' and the marginal flan 25 of a downwardly concave cover member 26, secured to the flange 2-3 in any desired manner, for exampleby means 01' bolts, notshown. The in ers 22 and 26 thus constitute a pneumatic motor casing which is divided by the diaphragm 24 into upper and lower chambers 2? and respectively. The ion c chamber communicates freely at allt ines with theouter chamberby means otcone or more large orii fices 29 in the member 22, while the chamber 27 communicates w'th the atmosphere by meansot' a single small orifice 29 preferably controlled by an adjustable needlevalvei j The central part otthe diaphragm i, preferably clamped betweenplates 30 and sinisposed uponits opposite sides and is secured totheupper end of the stem 32 of the valve 17 by means of a bolt whi c v n passes through the plates 3021110 31 and the central part of the diaphragm and has threaded engagement with an axial opening in the stern F or convenience in assemblage of the parts it is preferred to provide the upper wall'2l of the casing'lO with a central aperture which is normally covered by a removable plate 34: having a boss 35 provided u-ith a guideway for the stem 32 o f-the valve. 7 A rod 36'forming an extension of the stem 32 has scr w-threaded engagement at its low er end with apthr'eaded'opening in'the head of the bolt This rod 36 passes through 59 a guide opening in the upper end of a gland 7 having threaaed engagement with an opening in a boss 88 projecting from the cover 26. One end of a compression spring 39 bears against the inner surface of the gland 3?. This spring encircles the rod 36 and bears at its lower end against a collar 40' secured to the rod 36. By screwing the gland37 in or out the tension of he spring 39'1nay be varied the tendency of the spring being to depress thediaphragin and to retain it'in thenor-mal position indicated in full lines in Fig. 2. The upperend of the rod 36'is -screw threaded for the'reception dean adjustable; contact th'iinble 4-2.

' Thee 'ver 26"1sprovide-d at one side with,

auxiliary motor casing;- Y

The central part oi the diaphragm 46 is preferably.clamped between stiffening plates 49. .his diaphragm is provided with a stem member '50 sliding in a suitable guide ope-ning in a boss F0 at. the center or thebase members r lic? 'the'a Xiliary motor casing. The upper end 01', the stem 50 passes through the. diaphragm and tlie'plates l6 andis screw threaded for'engagement by a clamping nut 51. The stem 50 is furnished with. restricted axial passage 53 otsmall cross section which opens laterally through the side of the stem at the point outside of the auxiliary motor casing and which opens at its upper end at the point 55 into the upper chamber of the auxiliary motor. I A'valve disk 56 is secured to the lower end of the stem 50 and cooperates with an annu lar valve seat 57defining a valve orifice 58 which col acts the chamber 27 of the main motor with a passage 59 which leads to the chamber 1ft. of the controller casing. 1A gland 61 has threadedengagement.with an opening in a boss (iQprojecting from the top of the cover member 18 oi the auxiliary motor, casing. This gland is hollow and provides a seat for the-upper end of a coiled compression spring'63 whose lower end bears against the clamping nutbl of thestem 50. The spring; thus tends to depress the diaphragm/l6 to restoreit to the normal position indicated in Fig; 2. By turning the gland 61 the tension ot'the, spring may be varied. v V

"A bracket 66 is secured to the cover-unember 48 of the auxiliary motor casing" and terms support for a pivot pin 67constituting the fulcrum or 'lever 68"which is arranged to swing in the vertical DlHDGClGfiIIQCl by the stems 36 and 50; One end of a spring 78 is secured to the lever 68 at the point 7 The other end of the spring is secured to an eye bolt Yipnssing freely through suitable openings in the flanges of the main motor casing andwhich is provided with an valdjusting nut 75 at its lower endi -The opposite end ofthe'lever 68 is guided in its vertical swinging movement by a slot 70 in a bracket 71 secured to the top of a eads upwardly from the chamber 81ft}; the

tially as follows, it being assumed that when 4 outer air and at the junction of this passage with the chamber81 a valve seat surface 83 is provided. 1 o

A suitable vent valve, preferably a ball valve 84, is arranged within the chamber 81 and adapted to seat against the surface 83 to close thepassage 82. This valve is secured to the lower end of the stem 85' ex-' tending loosely through the passage 82 and pivotally connected at-the point 86 to the end 87 of th lever 68. The spring 7 8 is so tensioned as normally to retain the ball valve 84 against its seat so as to close the passage 82 and thereby to prevent entrance of air at atmospheric pressure into the upper chamber of the motor casing.

The'operation of the device is substan the transmission tube is idle the parts 00- cupy the position indicated in full lines in Fig. 2. \Vhen in this position the member 42 is spaced from the lower edge of the lever 68,the latter being substantially horizontal, and'the valve 84 rests against its seat. At this time a minimum flow of air is enteringthe open transmission terminal 2 of the tube 3 and circulating through the outlying station, the tube 4, pipe 6, and tube 20, is passing to the exhauster.

When a carrier is inserted in the trans missiontube, either at the point 2 or at the outlying station, the minimum flow of air is cut off or at least substantially diminished with resultant .increase in the" vacuum in the transmission l1ne. This decrease n pressure s immediately. transmitted through the passage 59 and the open valve orifice 58 to the chamber 27 of the main motor whereit becomes effective to raise the diaphragm 24,-against the resistance of the spring 39 andthns to open the main valve 17. As soon as the main valve opens to the slightest degree the vacuum in the transmission tube is further increased so that the diaphragm 24 rises with increasing force until the main valve isfully open. As the 'main valve approaches its fully open position the contact member 42 engages the lower edgeof the lever-.68 and tilts'the latter to the dotted line position indicated at 76in Fig. 2, the resistance of spring 68 being added to that of spring 39 in oppos ing this final movement of diaphragm 24. This movesthe end87 of thelever downwardly and thus unseats the, valve 84 permitting atmospheric pressure to enter freely 1 of the auxiliary ber 48 of the auxiliary motor. As the lower chamber 48 of this-motor is always freely open to the atmosphere through a vent 44, the diaphragm 46 tends to rise and thus to close the valve 56,- butas the passage 53 is so restricted the differential. I

pressures acting upon the opposite sides of. the diaphragm 46 tail to lift thediaphragm in opposition to the spring 63 until the main valve has had time fully toopen and thus to unseat'the valve 84. 1

So long. asthe valve 84' remains unseatedtheslow withdrawal of airfrom the chamber 48 'is unavailing to raise the diaphragm 46 so that the valve 56 remains open. 1

When the last. carrer emerges from the transmission tube, thevacuumin the trans} mission tube decreasesslightly by reason of the removal of the'trictiona-l drag of the carrier passing along the tube. This slight increase in pressure in the transmission tube p'ermlts the diaphragm 24 to move down toa shght extent responsive to its spring 39,

assisted by the spring 73, until the lever 68 ture-29 until the. pressure-upo-n opposite sides of the diaphragm 29rhas been nearly equalized, whereupon the spring 39 depresses the diaphragm' 24 and closes-the main valve 17,;thus cutting off thecarrier prfipelling air flow through the transmission tu e.

As soon'ias such flow is cutoff the pressure in the chamber 48 beginsslowly to rise as the air leaks in through the passage 56 and after a short interval thespring 63 restores the valve 56 to its normal open position.

By the arrangement described the opening of the main valve is accomplished automatically by the slight drop in pressure in the transmission tube incident to introduction of a carrier, and. this valve is positively held open until thelast carrier emerges from phericaair leaks inthrough thevalve aper;

ill)

the line. The slight-increase in pressure in.

ci dent to the deliveryof the last carrier then initiates closure of the main valve. The de vice thus operates independently of any timing arrangement and solely in accordance with the presence or absence of a carrier or carriers in the transmission tube. c

In my copending application, Serial No; 25,765,- vfiled April 25,1925, I have disclosed a modified arrangement-tor determining the time of closure of the auxiliary valve and have therein claimed my invention embodiment ottheinvent-ion, I wish it to be understood that various changes in relative position-and proportion of parts, as well as the substitution of'equivalents for the elements herein-specifically described may be made Without departing from the spirit of the invention.

I claim:

-1. Power control apparatus for a pneumatic dispatch system-of the vacuum minimum flow type having a transmission tube communicating with an eXhauster, ap paratus comprising aqmain valve for controlling carrier propelling air flow through the tube, a minimum flow of air through the tube being permitted when the valve is closed, a main pneumatic for operating the controlling valve, an auxiliary "pneumatic, an auxiliary valve actuable by the auxiliary pneumatic to vary the pressure acting upon the main pneumati'quneans tending to establish unbalancedpressure upon opposite sides of the auxiliary pneumatic'when carrier is inserted in the transmission tube and means actuable by-the main pneumatic to maintain a balanced-pressure upon opposite sides or the auxiliary" pneumatic so long as a carrier remains in the transmission. tube; s V "2. Power control apparatus for a pneumatic dispatch system having a transmission tube, means for creating carrier propelling air flow therein, said apparatus comprisinga main valve for controlling'carrier propelling airflow through the-tube, a ma-in motor for operating the controlling valve, control meansfor the main motor, a pneumatic constantlyexposed upon one side to atmospheric pressure, a normally closed pressure control valve for determining admission of atmospheric pressure to the opposite side of the pneumatic, means for transmitting movement from the main motor to said pressure control valve to open the latter and to hold it open so long as a carrier remains in the transmission tube, and means for transmitting'movement from the pneumatic to the control means of the main motor. .e '3. Power control apparatus for a pneumatic' dispatch system of the vacuum minimum flow type having atransmission tube communicating with an exhaustcr, said apparatus comprising a main valve for con trolling carrier propelling air flow through the tube, a minimum flow of air through the tube being permitted when the valve is closed, a main pneumatic for operating the controlling valve, an auxiliary pneumatic, a

normally closed vent valve for admitting atthe main pneumatic and the vent valve for opening the latter.

a. Power control apparatus for a pneu matic dispatch system having a transmission tube, and means for creating carrier propelling air flow therein, said apparatus comprising a main valve for controlling carrier propelling air flow through the tube, amain motor for operating the valve, control means for the mainmotor, a pneumatic for actuat-' in said control means a assa ewa constantly open being provided through which transmission tube pressure may be transmitted at all times to the" space at one side of the auxiliary pneumatic thereby tending to actuate the latter and thereby operate the control means for the main motor, and means actuable by the main motor top'revent the establishment of transmission line pressure in said space so longas a carrier remains the transmission tube.

5. Power control apparatus for a pneumatic dispatch system of the vacuum minimum flow type having a transmission tube commun cating with an exhauster, said ap paratus comprising amain valve for controlling carrier propelling'air flow through the tube, a minimum flow of air through the tube being permitted when the valve is a closed, a main pneumatic for moving the controlling valve, said pneumatic having a chamber communicating by means of a normally open passage with the transmission tube, an auxiliary valve for closing said pas-.

erating the air controlling valve, an auXiliary valve for controlling'pressure conditions in said fluid motor, a pneumatic for closing the auxiliary" valve, the pressure upon opposite sides of said pneumatic tend-. ing to become unbalanced when a carrieris inserted in the tube, a vent va-lve for the pneumatic and means for transmitting movement from said fluid motor tothe vent valve to open the latter and thereby to maintain a substantially equal pressure upon op= 'posite sides of-the pneumatic as long'as a carrier remains in the tube.

7. Pneumatic dispatch apparatus having a transmission tube, an exhausterconnected therewith, and a valve, for controlling the flow of air through the transmission tube, a minimunrfiow of airthrough the'tube being permitted when the valve is in closed position, a pneumatic main motor comprising a flexiblediaphragm' foroperating the air con? trolling valve, said diaphragm being connected to said valve, an auxiliary valve for controlling pressure conditions in the main motor, an auxiliary pneumatic motor comrisin a flexible dia Jhra in connected to the auxiliary valve, the pressureupon opposite sides of said auxiliary diaphragm tending to become unbalanced and thereby 'to close the auxiliary valve when a carrier is inserted in the transmission tube,- andmeans actuable by the main motor to preserve substantial equality of pressure upon opposite sides of said diaphragm so long as a carrier remains in the tuber y 8. Pneumatic dispatch apparatus having a transmission tube, and means for creating carrier propelling air flow therein, and a main valve for controlling the flow or air through the transmission tube, a pneumatic main motor comprising a flexible diaphragm for operating the main valve, means connecting said diaphragm to saidmain valve, an auxiliary valvefor controlling pressure conditions in the main motor, an auxiliary pneumatic motor comprising a flexible diaphragm connected to the auxiliary valve, one side of the auxiliary diaphragm being exposed to atmospheric pressure, the pres sure upon the othersideof said diaphragm tending to drop below atmospheric pressure when a carrier is placed in the transmission tube and thereby to close said auxiliary valve, a normally closed vent valve to admit atmospheric air to act upon said last named side of the pneumatic, means act-uable by the main motor for opening said vent valve when a carrier is placed in the tube and for holding said vent valve open so long as a carrier remains in the tube, and means tending to close the vent valve.

9. Power control apparatus for a pneumatic dispatch system of the vacuum mini mum flow type having a transmission tube communicating with an exhauster, said apparatus comprising a main valve for controlling carrler propelling air flow through the tube, a minimum flow of air through the tube being closed, a main pneumatic for operating the valve, a pressure control valve for the main pneumatic, a motor for actuating said control valve, said motor having a chamber, a flexible diaphragm forming one wall of the chamber, means connecting the diaphragm to the pressure control valve, there being a restricted passage for transmitting transmission tube pressure to said chamber, a vent valve for admitting atmospheric air to said chamber, the main pneumatic responding to drop in transmission tube pressure due to insertion of a carrier and therebyopening the main valve, and connections between the permitted when the valve is tube and means for creating a carrier propelling air flow therein, said apparatus comprisrngia main valve for controlling carrier propelling air flow through the tube,a main pneumatic-for operating the mainxvalve, a

pressure control valve for the main pneumatic, a motor for actuating saidcontro-l valve having a chambery'a flexible diaphragm forming onewall of the chamber, means connecting the diaphragm to the pressure control valve, there being. a restricted l passage for transmitting transmission tube pressure tosaid chamber, avent valve for controlling admission of atmospheric .air tosaid chamber, the main pneumatic respond ing to change in pressure in the transmission tube due to'insertion of a carrier therein, thereby to openthe main. valve, a lever connected to the vent valve, and meansactuable by the main pneumatic as ,the main valve approaches fully open position for rocking the lever and thereby moving the vent valve, i v Q 11, Power c ntrol apparatusfor'a pneumatic; dispatc systenrhaving 'aftransmise sion tube and means for creating carrier propelling air flow therein, said apparatus comprising a main valve for controlling carrier propelling air flow through the tube, a main motor for operating the valve, control means for the 'main motor, a pneumatic motor for actuating said control means, said pneumatic motor having a chamber, a flexible diaphragm forming one wall of the chamber, vmeans connecting the diaphragm to the control means for the main motor, there being a restricted passage for trans mitting transmission tube pressure to said chamber, a vent valve for controlling admission of atmospheric air to said chamber, the main motor having member, a lever having an element disposed in the path of movement of said reciprocating member but normally spaced therefrom, means connecting. said lever to the vent valve, and means acting upon the lever tending to close the vent valve, the main motor responding to insertion of a carrier in the transmission tube to open the main valve and to rock said lever whereby fully to open the vent valve, said mainmotor also responding to discharge of the last carrier from the transmission tube to permit the vent valve completely to close.

12. Power control apparatus for a pneumatic dispatch system of the vacuum mini mum flow type having a transmission tube communicating with an exhauster, said apa reciprocating p'aratus comprising a main valve for. con, trolling carrier-propelling air flow, through the tube, a minimu'n'i flow of air through the tube being permitted when the valve is closed, a main pneumatic motor :tor moving the controlling. valve, said motor having a casing divided into chambers by a movable septum, one of said chambers being "freely open to the atmosphere and the other phamber communicatin-gbly means of a passage with the transmission tube, a normally open auxiliary valve for closing said passage,

said'auxiliary.valvehaving a stem, an auXil-- iary pneumatic motor comprising a casing divided intocha-mbers by a movable septum, means connecting the movable septum to the stem ofthe auxiliary valve, one of the chambers of. the auxiliary motor being freely open to the atmosphere and the other normally closed to the atmosphere but communicatingby means of a restricted passage through the valve'stem with the transmis siontube, a normally closed vent valve for admitting atmospheric air to the latter chamber of the. auxiliary motor, means tend:- ing to. close said vent valve, and'me'ans actuable by the main motor for opening said vent valve and holding it open during fii'ght of a carrier through thetube.

13. Power control apparatus for ap neumatic dispatch system of the va'cuum minimum flow type having a transmission tube communicating with ane xhaust'er, snide apparatus comprising a mainvvalve for controlling carrier propelling air flow through the-tube, a minimum flow of air through the tube being permitted When the valve. is closed a main pneumatic motor comprising acasing havinga chamber therein, a. diaphragm formlng one Wall of said, chamber, said chamber normally communicating by meansof a passage with the transmission tube, the diaphragm havinga stem connecting it with the main valve an auxiliary valve controllingsaidpassage, anv auxiliary pneumatic motor comprising a casing having a chamber, aflexibl'e diaphragmulorming one Wall of said chamber, means con necting said latter diaphragm-With the auxiliary valve, the chamber of the auxiliary motor communicating I bymoarrs off-a re? stricted passage with the transmission tube and having an orifice in its wall' opening to. the outer air, a vent valve normally closing salid orific'e,a lever movable by the stem ofthe main motor diaphragm when the lat ter opens the main-valve, andi-neans connecting I the vent valve, with said lever whereby movement of the lever opens the valve. e Signed by me at Syracuse, New York, this twent -fifth day or March, 1925. I

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